Table 5.

Criteria used for grading evidence and strength of recommendations

	Use of criteria in guidelines			Totala, n (%)
	Not used, n (%)	Used but not defined, n (%)	Used and defined, n (%)
Criteria related to evidence
Susceptibility to bias of studies	6 (43)	0	8 (57)b	14 (100)
Quality of studies	1 (7)	9 (64)	4 (29)	14 (100)
How precise results are	13 (93)	1 (7)	0	14 (100)
Heterogeneity of results	8 (57)	6 (43)	0	14 (100)
Criteria related to outcomes
Size of beneficial effect	8 (57)	6 (43)	0	14 (100)
Risks	11 (79)	2 (14)	1 (7)	14 (100)
Costs	12 (86)	2 (14)	0	14 (100)

^aThere was no scale for grading evidence or strength of recommendations in three guidelines

^bThe best study designs were usually considered to be randomized clinical trials